U.S. Pat. No. 5,720,078 discloses a suction device for removing liquids from a surface such as a floor. The device includes an air chamber formed from a top and a bottom plate, each of the plates having a respective top and bottom surface. The bottom plate includes a plurality of holes therethrough. The bottom surface of the bottom plate additionally includes fabric adjacent thereto and feet to hold the bottom plate of the device up off the floor to enable fluid to be suctioned through the bottom plate holes and into the chamber via a conventional source of suction. In an embodiment, each of said holes is between 0.030 to 0.250 inches in diameter.
WO 2006/091439 discloses a cleaning implement that provides multiple functions useful in cleaning windows and similar surfaces. There is a support head mounting a squeegee blade and (optionally) a scrubber and/or touch-up pad. There is also a collector absorbent pad that is mounted to the support head adjacent the squeegee blade. The collector can be made of an absorbent such as a porous plastic. Particularly preferred absorbents are porous polyethylene materials available from Porex.
DE 102012104102 discloses an apparatus having a handle connected with a liquid applicator over a pivot, and a suction opening part movably arranged relative to the liquid applicator.
There are nowadays more and more electric driven products suited for surface cleaning, which replace, for example, the well-known mop and bucket for floor cleaning, or the sponge and squeegee for window cleaning.
For cleaning surfaces in general, three steps can be identified. Step 1: bringing a liquid to the surface. Step 2: an agitation action for loosening and dissolving the dirt. Step 3: taking up the dirt including part of the liquid. For this last step, there are in general two solutions. The most common way is using a cloth or sponge like material (absorption), sometimes in combination with a squeegee to first collect the liquid and then absorb by cloth. The second solution is used by electrical appliances. Many of these cleaning appliances use suction/airflow, mainly in combination with double squeegees. The squeegee wipes the liquid from the surface and is collected just in front of the squeegee. The suction or airflow will than transport the liquid to a reservoir.
A good liquid pick up after the cleaning action has several advantages, minimize risk on floor damage, reducing drying time and especially for window cleaning it reduces stripes after drying. Stripes are caused by the evaporation of the liquid, and residue will remain on the window.
The main disadvantage of the bucket and mop principle is that the amount of liquid that remains on the floor is difficult to control. It strongly depends on how well the mop is wrung (this determines the amount of liquid that remains in the mop and the amount of liquid that can be absorbed by the mop). Some buckets have a mechanical system that helps to wring the mop. Still the amount of liquid on the floor depends on the force the consumer puts on the wringer and also depends on the amount of force that is put on the mop by the consumer during cleaning the floor. This can result in a poor cleaning performance when the mop is too dry but even worse, it can result in damage to the floor when the mop is too wet.
The main disadvantage of window cleaning with sponge and squeegee is that the liquid is wiped of the window but is not collected by anything. This means that all the liquid runs down the window on to the window frame or window sill. There it can be dried by a cloth or sponge. But the liquid pick up is very little due to the limitations of absorption of the material. Consumers see this as a big hassle of wringing the cloth or sponge which results in liquid spillage etc.
A general disadvantage of the above mentioned manual cleaning methods is that the performance over time is not constant. A mop, cloth or sponge is getting increasingly dry during the cleaning action when releasing liquid to the surface, and is getting increasingly wet during the drying action when absorbing liquid from the surface.
Electric cleaning appliances solve the above issues by wiping the liquid from the surface by a squeegee and applying suction/airflow to transport the collected liquid to a reservoir. In general this is done by a double squeegee system. The main issues for the above mentioned system are that a rather big fan/motor must be used to generate sufficient airflow to transport the liquid, that the air and the liquid needs to be separated again and the fan/motor must be suited to handle moist or moist air. That means that this system is expensive and complex.